Many devices have been used previously for determining whether electrical current is being drawn through AC power lines. Some of these, such as the Watt Watcher device disclosed in U.S. Pat. No. 4,717,872 are used to control power consumption. The Watt Watcher device is substantially a clamp that fits about an AC power cord and uses an induction type sensor. Other types of induction sensors, which generally consist of a ring or clamp encircling a power line, are well known, such as Bubash, U.S. Pat. No. 5,015,944. Some of these devices are complex and are not readily adaptable for connection to feedback circuits to control electrically operated equipment.
It is therefore an object of the present invention to provide a power monitoring circuit for indicating whether current is flowing through an AC power cord. Another object of the invention is to provide a device which simply slips on to the plug blades of an AC power cord and does not require removal and re-wiring of the cord. Yet another object of the present invention is to provide a device that readily connects to controlling devices to provide an indication of power flow.
Other objects and advantages of the present invention will be apparent to those skilled in the art from the following Summary of the Invention and Description of the Preferred and Alternate Embodiments.